JP2006164581A - Sensor feeler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensor feeler which can avoid an operation failure even if burrs generated on the circumference of the tip edge of a feeler axis collapse. <P>SOLUTION: The sensor feeler 1 is equipped with the feeler axis 31 as the rotary axis, and a contact member 32 and a light shield member 33 which are each projected on the outer peripheral surface 31c of the axis. By contact of a manuscript copy (detection object) 22 with the contact member 32, they rotate about the axis center of the feeler axis 31 to intermit light-shield by the light shield member 33. A chamfered part 61 is formed on the periphery of the tip edge 31e of the feeler axis 31 such that the projected length B, of the burrs 62 generated on the circumference of the tip edge 31e of the feeler axis 31, from the tip edge 31e of the feeler axis 31 is smaller in the axis direction than the chamfered dimension M in the perpendicular direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is rotatably provided in a sensor for detecting a detection object such as a document conveyed by an automatic document conveyance device or the like, a recording sheet accommodated in a paper feed cassette or the like, and is brought into contact with the detection object. The present invention relates to a rotating sensor feeler.

This type of conventional technology includes a feeler shaft as a rotation shaft, a contact member and a light shielding member projecting from the outer peripheral surface of the feeler shaft, and the shaft of the feeler shaft by contact of the detection target with the contact member. A sensor feeler that rotates around a center and interrupts light shielding by a light shielding member is known (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 10-129987 (page 2-3, FIGS. 1 to 3 etc.)

  Since many of the conventional sensor feelers as described above are injection molded products of synthetic resin, burrs projecting in the axial direction may occur on the periphery of the tip surface of the feeler shaft depending on the mold configuration. This burr is often crushed when the tip of the feeler shaft is inserted into a mounting hole provided in an automatic document feeder or the like. Since the burrs that are crushed when they are inserted into the mounting holes are wound between the tip of the feeler shaft and the mounting holes, there are crushed burrs where the tip of the feeler shaft contacts and rotates. Will do. In this case, the gap between the tip end of the feeler shaft and the mounting hole becomes narrow, or the contact surface of the tip end of the feeler shaft with respect to the mounting hole becomes uneven. There is a problem that it may cause malfunction.

  The present invention has been made in view of the problems as described above, and provides a sensor feeler that can avoid malfunction even when a burr generated on the peripheral edge of the tip surface of the feeler shaft is crushed. Objective.

  The invention of claim 1 for achieving the above object comprises a feeler shaft as a rotating shaft and a contact member and a light shielding member projecting from the outer peripheral surface of the feeler shaft, respectively, and the contact of the object to be detected with the contact member. A sensor feeler that rotates about an axis of the feeler shaft and interrupts light shielding by the light shielding member, and a protrusion length of the burr generated at the periphery of the tip end surface of the feeler shaft from the tip end surface of the feeler shaft is A chamfered portion is formed on the peripheral edge of the tip surface of the feeler shaft so as to be smaller than a chamfer dimension in a direction perpendicular to the axial direction of the feeler shaft.

  According to the first aspect of the present invention, the protruding length of the burr generated from the tip end surface of the feeler shaft at the periphery of the tip end surface of the feeler shaft is smaller than the chamfer dimension in the direction perpendicular to the axial direction of the feeler shaft. Since the chamfered portion is formed on the periphery of the tip end surface of the feeler shaft, even if the burr is crushed when the tip end of the feeler shaft is inserted into the mounting hole, the burr is between the tip end portion of the feeler shaft and the mounting hole. Therefore, it is possible to avoid malfunction of the sensor feeler.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 to 6, the sensor feeler 1 according to the present embodiment constitutes a part of a lead sensor 4 built in an automatic document feeder 3 of an image forming apparatus 2. Examples of the image forming apparatus 2 include a copying machine, a printer, a facsimile machine, and a digital multifunction machine having a plurality of functions such as a print function, a FAX communication function, a copy function, and a scan function.

  As shown in FIGS. 2 and 3, the automatic document feeder 3 automatically and continuously serves as a document feeder (ADF) for a plurality of documents (detected objects) placed on the document tray 11. The sheet is conveyed so as to make a U-turn through a substantially U-shaped conveyance path 13 to the lower discharge tray 12. There are two reading positions P1 and P2 in the middle of the conveyance path 13, and images on one side and the other side of the document are sequentially read at these two reading positions P1 and P2. At the upstream reading position P1, an image on one side of the document is read by a CCD reading unit 15 having a CCD (Charge Coupled Device) 14. At the downstream reading position P2, an image on the other side of the document is read by a CIS (Contact Image Sensor) reading unit 16. Each image information read by the CCD reading unit 15 and the CIS reading unit 16 is transmitted from an image reading control unit (not shown) to the main body control unit.

  As shown in FIG. 3, the lead sensor 4 having the sensor feeler 1 is provided in front of the downstream reading position P2. As shown in FIGS. 4 to 6, the lead sensor 4 includes a rotation detector 21 in addition to the sensor feeler 1 as a main constituent member. As shown in FIG. 4, the lead sensor 4 detects the leading end 22a and the trailing end (not shown) of the document (detection target) 22 being conveyed, and sequentially transmits each detection signal to the image reading control unit. is there. Based on each detection signal received from the read sensor 4, the image reading control unit starts reading an image after a predetermined time has elapsed since the leading edge 22 a of the document 22 is detected, and after the trailing edge of the document 22 is detected. The CIS reading unit 16 is controlled so as to end the image reading after a predetermined time has elapsed.

  The sensor feeler 1 is formed of a synthetic resin injection molded product or the like, and includes a feeler shaft 31, a contact member 32, and a light shielding member 33, as shown in FIGS. As shown in FIG. 5, the feeler shaft 31 is formed in a round bar shape, and one end portion 31 a and the other end portion (tip portion) 31 b are formed narrower. The feeler shaft 31 may be formed to have the same diameter as a whole without forming the one end 31a and the other end 31b thinner. As shown in FIGS. 4 and 5, the contact member 32 is formed in a substantially triangular plate shape, and is perpendicular to the axial direction on the outer peripheral surface 31 c of the feeler shaft 31 (the radial direction of the feeler shaft 31). Projected to On the end surface of the contact member 32, a slope portion 32a is provided to make it easy to slide and press when the leading end 22a of the document 22 comes into contact. Further, as shown in FIG. 4, the contact member 32 is provided with a triangular through hole 32b penetrating in the thickness direction in order to save material costs. The light shielding member 33 is formed in a substantially L-shaped plate shape from a base portion 33 a protruding from the outer peripheral surface 31 c of the feeler shaft 31 and a protruding portion 33 b protruding from the base portion 33 a in the direction opposite to the contact member 32.

  As shown in FIGS. 2 to 4, a platen roller 41 is provided below the CIS reading unit 16 to convey the original 22 while pressing the original 22 against the reading surface. The platen roller 41 is accommodated in a recess 43 provided on a support body 42 made of synthetic resin or the like so as to extend in a direction perpendicular to the conveyance direction of the document 22. As shown in FIGS. 5 and 6, a pair of mounting plates 44 opposed to the lower surface 42 d upstream of the concave portion 43 of the support 42 with a predetermined interval in the direction perpendicular to the conveying direction of the document 22. Is protruding. Each of the pair of mounting plates 44 is formed with a mounting hole 45. One end 31 a of the feeler shaft 31 is inserted through the mounting hole 45 of one mounting plate 44, and the other end 31 b is inserted through the mounting hole 45 of the other mounting plate 44. The sensor feeler 1 is attached to a pair of attachment plates 44 so as to be rotatable about the axis of the feeler shaft 31 so that the inclined surface portion 32a of the contact member 32 and the protruding portion 33b of the light shielding member 33 face the upstream side. It has been. An opening 46 is provided between the pair of mounting plates 44 in the support 42. From the opening 46, the contact member 32 can freely appear and disappear. The sensor feeler 1 is urged so that a part of the contact member 32 protrudes upward from the support 42 by a spring member (not shown) fitted on the feeler shaft 31.

  As shown in FIGS. 5 and 6, a stop plate 47 is provided on the lower surface 42 d of the support 42 outside the one mounting plate 44 so as to protrude in a direction perpendicular to the conveying direction of the document 22. The one end 31a of 31 is restrained from moving outward. Further, on the lower surface 42d of the support 42 inside the other mounting plate 44, a pair of stop rods 48 is formed to be smaller than the diameter of the other end portion 31b in which the feeler shaft 31 is formed narrower in the conveyance direction of the document 22. The feeler shaft 31 is restrained so as not to move outward by the pair of restraining rods 48 because it is provided so as to be opposed to each other with a slight gap therebetween. The insertion of the other end 31b of the feeler shaft 31 into the attachment hole 45 of the attachment plate 44 is performed by first inserting the one end 31a of the feeler shaft 31 into the attachment hole 45 of one attachment plate 44 as shown in FIG. Thereafter, the other mounting plate 44 is bent outward.

  As shown in FIGS. 5 and 6, the rotation detector 21 includes a light emitting unit 51 and a light receiving unit 52 that are opposed to each other at a predetermined interval in a direction perpendicular to the conveyance direction of the document 22 as main constituent members. . The light emitting unit 51 emits the detection light L toward the light receiving unit 52. The sensor feeler 1 is attached so that the protruding portion 33 b of the light shielding member 33 is positioned between the light emitting portion 51 and the light receiving portion 52. Therefore, the detection light L emitted from the light emitting unit 51 is shielded by the protruding portion 33b. As shown in FIG. 4, when the leading end 22a of the conveyed document 22 comes into contact with the inclined surface 32a of the contact member 32 of the sensor feeler 1 and the contact member 32 rotates downward, the light shielding member 33 rotates upward. To do. Thus, the sensor feeler 1 rotates by a predetermined angle, the detection light L emitted from the light emitting part 51 of the rotation detector 21 enters the light receiving part 52, and the light shielding of the detection light L by the protruding part 33b of the light shielding member 33 is interrupted. Then, a detection signal is transmitted from the image reading control unit to the main body control unit, and reading of an image by the CIS reading unit 16 is started after a predetermined time has elapsed. Thereafter, when the rear end of the document 22 passes through the contact member 32, the contact member 32 and the light shielding member 33 are rotated in the opposite directions by the elastic force of the spring member (not shown). In this way, if the sensor feeler 1 rotates in the reverse direction and the detection light L is shielded by the protrusion 33b of the light shielding member 33, a detection signal is transmitted from the image reading control unit to the main body control unit, and after a predetermined time has elapsed. Image reading by the CIS reading unit 16 is completed.

  As shown in FIGS. 4, 7, and 8, a chamfer 61 and a burr 62 are formed on the periphery of the tip surface 31 e of the other end 31 b of the feeler shaft 31 of the sensor feeler 1. The burr 62 is formed in a ring shape so as to protrude in the axial direction from the peripheral edge of the tip end surface 31 e of the feeler shaft 31. The protruding length B of the burr 62 from the tip end surface 31 e of the feeler shaft 31 is configured to be smaller than the chamfer dimension M of the chamfer 61 in the direction perpendicular to the axial direction of the feeler shaft 31. Therefore, as shown in FIGS. 5 and 6, even if the burr 62 is crushed when the other end portion 31 b of the feeler shaft 31 is inserted into the attachment hole 45 of the other attachment plate 44, the other end of the feeler shaft 31 is removed. There is an advantage that the burr 62 is not caught between the portion 31b and the mounting hole 45, so that the malfunction of the sensor feeler 1 can be avoided.

  The cross-sectional shape of the chamfered portion 61 is not particularly limited, and may be an arc shape as shown in FIG. 9 in addition to a linear shape as shown in FIG. Further, the protruding direction of the burr 62 may be a direction perpendicular to the axial direction of the feeler shaft 31 or an oblique direction in addition to the axial direction of the feeler shaft 31. Further, the sensor having the sensor feeler 1 includes a document 22 conveyed by the automatic document feeder 3 as shown in FIGS. 1 and 2, a paper feed cassette 71 provided in the image forming apparatus 2 as shown in FIG. May be used for detecting various detection objects such as recording paper (not shown) accommodated in the storage medium. Such sensors include the lead sensor 4 provided in front of the downstream reading position P2, the lead sensor 72 provided in front of the upstream reading position P1 as shown in FIG. A document length sensor 73 or a document width sensor 74 provided on the side, a recording sheet sensor (not shown) incorporated in the sheet feeding cassette 71 as shown in FIG. Similarly to the downstream lead sensor 4, the upstream lead sensor 72 detects the leading end 22a and the trailing end of the document 22 being conveyed, and sequentially transmits each detection signal to the image reading control unit. Based on each detection signal received from the upstream side read sensor 72, the image reading control unit starts reading an image after a predetermined time has elapsed since the leading edge 22a of the document 22 is detected, and the trailing edge of the document 22 is detected. Then, the CCD reading unit 15 is controlled so as to end the image reading after a predetermined time has elapsed. The document length sensor 73 detects the length of the document 22 in the conveyance direction. The document width sensor 74 detects a width in a direction perpendicular to the conveyance direction of the document 22. The recording paper sensor detects the presence or absence of recording paper in the paper feed cassette 71.

  As described above, the sensor feeler according to the present invention is suitable for avoiding malfunction even when a burr generated on the peripheral edge of the tip surface of the feeler shaft is crushed.

1 is a schematic perspective view of an example of an image forming apparatus. FIG. 2 is a schematic sectional view of an automatic document feeder provided in the image forming apparatus of FIG. 1. FIG. 3 is a schematic diagram of a conveyance path in the automatic document conveyance device of FIG. 2. Operation | movement explanatory drawing of the sensor feeler which concerns on embodiment. FIG. 5 is an explanatory view of the attachment state of the sensor feeler as seen from the left direction in FIG. 4. FIG. 6 is an explanatory diagram of an attachment state of the sensor feeler as viewed from the lower side of FIG. 5. Explanatory drawing which shows a mode that the sensor feeler of FIG. 5 is attached to a pair of attachment board. Explanatory drawing which shows a mode that the other end part of the feeler axis | shaft of the sensor feeler of FIG. 7 is penetrated to the attachment hole of another attachment plate. Explanatory drawing which shows the example which made the cross-sectional shape of the chamfer part arc shape.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sensor feeler 31 Feeler axis | shaft 31c Peripheral surface 31e Front end surface 32 Contact member 33 Light-shielding member 61 Chamfering part M Chamfering dimension 62 Burr B Protrusion length

Claims (1)

The light-shielding member includes a feeler shaft as a rotation shaft and a contact member and a light-shielding member projecting from the outer peripheral surface of the feeler shaft, and rotates around the axis of the feeler shaft by contact of the detection target with the contact member. A sensor feeler that interrupts light shielding by
The tip of the feeler shaft is such that the protruding length of the burr generated at the periphery of the tip surface of the feeler shaft from the tip surface of the feeler shaft is smaller than the chamfer dimension in the direction perpendicular to the axial direction of the feeler shaft. A sensor feeler characterized in that a chamfered portion is formed at the periphery of the surface.

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